Devices with flexible shafts are often required to guide endoscopes to target sites within a body lumen or cavity. Such a guide shaft provides a semi-rigid structure through which an endoscope may be passed without causing damage thereto. Criteria for guide shafts may vary according to the procedure being performed but may include, among others, a combination of varying levels of kink resistance, crush resistance, flexibility, etc. Although these flexible shafts are often formed as coils, the ability of many of these coils to transmit rotational forces along their lengths is insufficient for certain applications.